E = 2.71828182845904523536028747135266249775724709369995; // Natural number.

// Ratio of a circle's circumference to it's diameter.
PI = 3.14159265358979323846264338327950288419716939937510;

// Golden ratio.
PHI = 1.61803398874989484820458683436563811772030917980576;

// A set of common square roots.
SQRT_2 = 1.41421356237309504880168872420969807856967187537694;
SQRT_3 = 1.73205080756887729352744634150587236694280525381038;
SQRT_5 = 2.23606797749978969640917366873127623544061835961152;
SQRT_7 = 2.64575131106459059050161575363926042571025918308245;

IN = 25.4 * MM;
FT = 304.8 * MM;
YD = 914.4 * MM;
MI = 1609344.0 * MM;
THOU = 0.0254 * MM;
MIL = THOU;

INCH = IN;
FOOT = FT;
FEET = FT;
YARD = YD;
MILE = MI;
